Polar View Research Articles

Anatomy and Pollen Morphology of Lantana camara L. - An Invasive Alien Plant

Lantana camara L. the alien-invasive species to Uttarakhand belongs to the verbenaceae family, ever-green woody shrub with different colour flowers ranges from yellow to orange. The fresh hand sections of stem and leaf of Lantana camara L. were studied with light microscopeand intended to find out identical characteristics. Epidermiswas a single layer of compactly arranged by barrel-shaped parenchyma cells with slightly thick walled where intercellular spaces were absent. The visually large trichomes were non-glandularand unicellular, conical type, presenting a large base and a thin extremity.Hypodermis was characterized by a few layers of collenchyma cells with angular thickenings.Cortex was represented by several layers of loosely arranged parenchyma cells with prominent intercellular spaces. Endodermis was having compactly arranged barrel shaped cells.The phloem and xylem cells located at upper and lower of 3 cell cambium layer respectively.Pith was also represented a group of loosely arranged parenchyma cells.The epidermis layer of leaves were uniseriate with regular size cells, was wrapped with a thick cuticle on the adaxial surface. Complex diacytic and anomocytic type of stomata’s were found. Non-glandular trichomes were found scattered through the entire petiole and leaf blades, are of the conical type, presenting a large base and a thin extremity, and ornamentations on the wall. The vascular system was open, forming a flattened arch in the “V” shape with two accessory bundles located dorsally and groups of idioblasts located laterally in the cortical parenchyma.SEM (Scanning electron microscopy) images and Optical microscopy of Pollens of the Lantana camara L. were also performed.Thepalynological information were recorded as sculpturinglooks smooth and the pollen type is tricolporate. Its shape in polar view is Semi-angular while equatorial view is spheroidal. The polar and equatorial diameter were 34μm (30-40μm) 33μm (30-40μm) respectively.

Palynological investigation of some selected species of family Fabaceae from Pakistan, using light and scanning electron microscopy techniques.

Pollen morphology of 11 species of family Fabaceae that is, Trifolium alexandrinum, Trifolium resupinatum, Arachis hypogaea, Lathyrus aphaca, Medicago lupulina, Vicia sativa, Lathyrus odoratus, Pongamia pinnata, Melilotus indicus, Medicago polymorpha, Medicago sativa from Pakistan has been investigated by light and scanning electron microscopy. Pollen were generally tricolporate, radially symmetrical, isopolar, elliptic in equatorial view and triangular in polar view under LM. Results showed that pollens were per-prolate (T. alexandrinum), prolate (T. resupinatum, V. sativa, L. odoratus, Melilotus indicus, M. polymorpha, M. sativa) and sub-prolate (A. hypogaea, L. aphaca, M. lupulina, P. pinnata). The larger polar/equatorial (P/E) ratio was found in T. alexandrinum (2.26 μm) and the smallest was found in M. lupulina (1.21 μm). The exine of T. resupinatum was 3.00 μm in thickness while others posses smaller exine thickness. The larger pore diameter was found in P. pinnata (16.01 μm) while others have smaller. The length of colpi was larger in Arachis hypogaea (32.24) while others posses smaller. Eight types of surface ornamentation (Psilate, faintly rugulate). Perforate and rugulate to verrucate have been observed under SEM. The pollens were europalynous type. Pollen morphology proved to be useful for the specific delimitation and serve as a tool for the identification and classification of taxa at specific and generic levels and can also be used as a key for the taxonomic features. Diversity in exine sculpture is helpful indicative characters for the isolation of closely related species. Hence, it is clear that both qualitative and quantitative characters of pollen can be useful for differentiating between taxa at specific level.

The Tale of Two Newspapers: Perceptions and Representations of Iranian International Relations Discourse

One of the research topics which intrigues researchers in the subject areas of applied linguistics, international relations and politics is political discourse and the way it is perceived and represented in the media. Researchers have analysed and interpreted the political and international relations discourse of various politicians and diplomats in different countries. By the same token, Iran, as a country with an influence on the political issues of the Middle East and a role in international dynamics and trends, has devoted a plethora of research to itself where researchers have examined and critiqued the international and foreign policies of Iran in various periods of time, in relation to various countries and in connection with various political and international events and situations. However, a search carried out by the present researcher showed that there are not many publications on how the British mass media, newspapers in particular, perceive and represent the Iranian government’s international relations discourse. To address this lacuna, a corpus of news stories and reports extracted from two renowned British newspapers, the Guardian and Daily Mail, was analysed by adopting a double hermeneutic content analysis approach. The results suggest that the two newspapers, in spite of being famous for having polar political views, seem to have similar perceptions and representations of the above discourse. The study also provides directions for further research in other contexts.

Pollen morphology of Aletris L. (Nartheciaceae) and its systematic significance.

In this paper, we studied pollen morphologies of seven species in genus Aletris in detail by light microscopy and scanning electron microscopy. Of these, six species were reported for the first time. The palynological characteristics do not support the infrageneric classification into two clades. The results indicated that pollen grains of Aletris are small or medium with the P/E ratio of 0.36-0.59. They are elliptic or long-elliptic in the polar view with blunt, round or acute ends and bilateral symmetric with a monosulcate, narrow or wide, deep colpus that has length extending to the ends of pollen grains, obvious or absent colpus membranes. The pollen ornamentation is gemmate, perforated, or reticulate. The sexine is slightly or quite thicker than the nexine.

A New Species of Coniopteris moguqiensis sp. nov. from the Middle Jurassic Wanbao Formation in Eastern Inner Mongolia, China

In recent years, an increasing number of plant fossil leaves and petrified woods have been discovered from the Middle Jurassic Wanbao Formation in Moguqi Town of Inner Mongolia, NE China. Here, we describe a new species of Coniopteris moguqiensis sp. nov. preserved as a fragment with fertile and sterile pinnules. The sterile ultimate pinnules are elongate ovate with sphenopteriod type venation, and fertile pinnules are usually isolated, bipinnate at least with the sorus apical, elliptical, 1 mm in diameter; sporangia are almost globular, 100–150 μm in diameter, and the annulus is vertical. In situ spores are rounded‐triangular in polar view, 25–30 μm in diameter with sides straight and slightly convex; trilete, laesurae are thin and slightly straight; the exine surface is usually psilate under the light microscope but finely reticuloid sculptured on the proximal view under a scanning electronic microscope. The fern genus Coniopteris usually suggests a warm and humid environment, which is consistent with the palaeoclimatic conditions of petrified wood and megafossil plants. The new discovery further supplements the floral composition of the Wanbao Formation, providing new material for understanding the evolutionary trend and classification of Coniopteris.

Description of seed and pollen micromorphology and their taxonomic impact in some Solanum L. species

Seed micromorphology, of 17 species and pollen micromorphology of 16 species of Solanum L. (Solanaceae) were examined using both light and scanning electron microscopy (SEM) to determine the significance of seed coat features and pollen characteristics as taxonomic characters. The species, used in this study, represent three subgenera and 11 sections of Solanum in Egypt. Macro and micro-morphological characters including seed shape, size, colour, surface; hilum shape, size, position, level; seed coat appearance, cell wall; shape of pollen in polar and equatrorial view, colpus membrane and apices and exine ornamentation have been described and their taxonomic impacts have been outlined. Seed shape was either obovate or reniform and seed size ranged between 1.1and 3.8 mm in length and 0.9 to 3.1 mm in diameter. Four types of seed coat appearance have been described: reticulate, cerebelloid, striate and without conspicuous cell lumen and six types of pollen shape were found in the studied species: prolate, subprolate, spherical, prolate-spheroidal, oblate-spheroidal and perprolate. Pollen length in polar view ranged from 15 µ to 34 µ but in the equatorial view it ranged from 9.1 µ to 25 µ. Four types of exine ornamentation have been recognized: scabrate, psilate, granulate and verrucate. Nineteen characters of seed and pollen micromorphology features proved useful in the construction of a dichotomus indented systematic key for the examined species. The major remarks are the differentiation of S. melongena, S. schimperianum, S. forsskaolii and diphyllum by their reinform seed shape from the remaining species which have ovoid seed shape. Hairy seed surface distinguishes Solanum lycopersicum, S. seaforthianum, S. nigrum and S. vilosum. Seed coat colour, appearance and pollen shape were useful traits for the identification of other nine species.

Taxonomic significance of pollen morphology in Succisa and Succisella

Abstract Pollen morphology of representatives of the genera Succisa and Succisella in the flora of Ukraine was studied using light and scanning electron microscopy. Pollen grains in both taxa were tricolpate, prolate, rarely oblate-spheroidal or spheroidal; large-sized. Their outline in polar view was subcircular, rarely trilobate, in equatorial view elliptical or rarely circular. Colpi short, of variable width, margins irregular with distinct, narrow margo, and blunt or acute ends. Exine sculpture was echinate-microechinate. The revealed characteristics of pollen grains are taxonomically significant at the generic and specific levels, and they can be used in pollen analysis. Palynomorphological data are consistent with the results of recent molecular phylogenetic studies. Data on pollen morphology also confirm taxonomic circumscription of Succiseae V. Mayer & Ehrend. Pollen grains in Succiseae are characterized by a tricolpate aperture type, which was probably ancestral in Dipsacaceae s. str.

Systematic relevance of pollen morphology in tribe Hylocereeae (Cactaceae).

Hylocereeae is one of the nine tribes in the subfamily Cactoideae (Cactaceae), for which the limits and recognition of genera have been controversial. Essentially, this group comprises epiphytic and hemiepiphytic genera with stems modified as climbing structures. The aim of this paper is to examine pollen attributes in representative species of genera of Hylocereeae, focusing on Selenicereus whose current circumscription comprises Hylocereus and three Weberocereus species, to find whether significant potentially apomorphic and/or autapomorphic systematic characters can be discovered. Utilizing SEM and light microscopy, 25 pollen characters were observed and measured. Tribe Hylocereeae is stenopalynous, with pollen grains isopolar and radially symmetrical monads, mostly tricolpate, except in Kimnachia, Pseudoripsalis and Weberocereus, whose pollen grains are pantocolpate. Seven attributes (five qualitative and two continuous) exhibited useful variation and were coded. The character of brevicolpate pollen grains was shared by Kimnachia ramulosa and Pseudorhipsalis amazonica. Convex quadrangular outline in the polar view was shared by Weberocereus tunilla and S. glaber. The absence of spinules on the exine was shared by S. minutiflorus and S. stenopterus. The largest pollen grain, found in Selenicereus megalanthus, might be correlated with polyploidy. Selenicereus is the taxon with the highest variation in pollen attributes, including species with an exine with or without spinules and variable polar area index and shape (subprolate or oblate-spheroidal).

Polarized views unchanged

Polarized views unchanged

Using Q methodology to investigate the views of local experts on the sustainability of community-based forestry in Oddar Meanchey province, Cambodia

Deforestation has become an issue of public interest and sensitivity in Cambodia. Community-based forestry (CBF) and the accompanying local institutional community forestry (CF) arrangements are increasingly recognized as successful mechanisms to achieve sustainable forest management. However, in most community-managed forestry studies, there has still been no significant exploration of the viewpoints of local people to determine the monitoring and actions needed to enable CBF to achieve sustainable forest management. Therefore this study examines the perspectives of local experts across a range of issues and challenges facing CBF sustainability, using Q-methodology. This paper adapted and used four criteria for sustainable forest management to design the 43 Q-statements to guide examination of the subjectivity of local experts concerning CBF sustainability in Cambodia. The 52 respondents were purposively selected from the 13 Community Forestry sites to Q-sort the Q-statements. The findings revealed that most local experts felt that the environmental condition (criteria I), the loss of forest, is critical but one factor strongly disagreed. Considering socio-economic benefits and needs (criteria II), there were similarly polar views about whether the community desperately needs external finance now or whether they have the collective will to act and need to show that first. Only one of the factors supported further REDD+ projects reasonably strongly; others valued eco-tourism opportunities. None of the factors ranked the quality of community-based forest management practices (criteria III) strongly although there was mild agreement about a lack of CF management accountability. There were contrasting views on the legal, policy, and institutional framework and governance (criteria IV), with disagreement about the importance of local enforcement, and quality of local communication and consultation. All agreed, however, that the current position does not give them meaningful ownership and control over forest resources.

Pollen morphological variation of Berberis L. from Pakistan and its systematic importance.

Due to overlapping and diverse morphological characters, Berberis is among the most taxonomically complex genera. Palynology is one of the taxonomic tools for delimitation and identification of complex species. In this study, pollens of 10 Berberis species were analyzed through light and scanning electron microscopy. Qualitative as well as quantitative features (pollen shape, size, presence or absence of colpi, colpi length and width, exine thickness, ornamentation, pollen class, aperture, and polar-equatorial ratio) were measured. Five species were observed to have colpate (pantocolpate) with elongated ends, radially symmetrical, isopolar, monads, and psilate-regulate pollens. In polar view, six pollen were spheroidal, two were ovoid, one spherical, and one oblate. Similarly, variation in pollen length was prominent and the largest pollen on polar view was recorded for B. psodoumbellata 60-65 μm (62.4 ± 0.9), while the smallest one was observed for B. lycium 29-35 μm (32.2 ± 1). The observed variation in both quantitative and qualitative features were important in taxonomic identification. This shows that palynological characters are helpful in identification of Berberis genus at the species level.

Pollen morphological study on some rare Allium L. (Amaryllidaceae) taxa in Turkey

The pollen morphology of 10 Allium L. taxa, 6 of which are endemic to Turkey, were investigated in detail by light and scanning electron microscopy. According to LM and SEM, the pollen grains of genera were monad, monosulcate percolate, heteropolar with bilateral symmetry, 25.30 to 53,85 µm long axis (LA) and 17.55 to 36.86 µm short axis (SA), the form was prolate (mean of LA/SA ratio 1.30 to 1.70 and in polar view boat-shaped. Three types of ornamentation were determined. Striate-rugulate-perforate type in Allium longisepalum, A. oreophilum, A. anacoleum, A. microspathum, A.shirnakiense, A. purpureoviride and A. armenum, Rugulate–perforate type in A. pervariense and A. gabardagense and Rugulate–reticulate-perforate type in A. arlgirdense. Sulcus membrane ornamentations were rugulate or psilate. The sulcus extends from the distal to proximal ends in A. anacoleum, A. arlgirdense and A. pervariense. The present study on some Turkish species of Allium showed that several morphological pollen characters may possess taxonomical value.

Evolution of Angiosperm Pollen. 7. Nitrogen-fixing Clade

Nitrogen-fixing symbiosis in root nodules is known in only 10 families, which are distributed among a clade of four orders and delimited as the nitrogen-fixing clade. As the seventh in a series that examines pollen morphological distribution and evolution in the angiosperms, this paper focuses on pollen morphological character states of the nitrogen-fixing clade. To illustrate the palynological diversity of the clade, we first examined pollen grains from 26 species with light electron, scanning electron, and transmission electron microscopy. Second, we used a reduced data matrix from Li et al. (2015) to reconstruct a maximum likelihood tree and then optimized 18 pollen character states onto the tree using Fitch parsimony, maximum likelihood, and hierarchical Bayesian inference. Finally, 12 plesiomorphic states for the nitrogen-fixing clade were inferred unambiguously under all methods, and more than 40 clades (or lineages) at or above familial level were characterized by unambiguous pollen character state changes in at least one of the optimizations. We found a number of evolutionary trends for changes in pollen character states. These include increasing grain size, increasing aperture number accompanied by concomitant changes in aperture position (from equatorial to global) and aperture shape (from colpate to colporate), and increasing complexity of tectum ornamentation. There was a strong correlation between some pollen characters (prolate shape class, lobe outline in polar view, colpate ectoaperture, lalongate and lolongate endoaperture, absent supratectal element, reticulate tectum) and insect pollination, while other pollen characters—simple aperture structure, porate ectoaperture, circular endoaperture, present and gemmate or echinate supratectal element, and imperforate tectum—were strongly correlated with wind pollination. In addition, rugulate tectum was significantly correlated with shrub habit while larger pollen size was significantly correlated with vine habit; the helophytic habitat was significantly correlated with having two apertures. Our study provides rich evidence for the phylogenetic significance of pollen morphological diversity in the nitrogen-fixing clade.

Pollen morphology of subfamily Maloideae (Roseaceae) with special focus on the genus Photinia

Pollen morphology of 27 species of Photinia sensu stricto and five closely related genera of subfamily Maloideae (Rosaceae) were studied in detail. Palynomorphological characteristics were examined using scanning electron microscopy (SEM). Comparative pollen analysis was accomplished based on pollen size, shape, polar and equatorial views, polar and equatorial diameter ratio (P/E ratio), width of aperture, and exine ornamentation. The pollen grains of studied species were found to be monad, tricolporate, small to medium in size (P=17.42–30.45 μm, E=9.26–20.18 μm) and to have shapes oblate-spheroidal (0.88–1.0 μm), prolate-spheroidal (1.01–1.14 μm), sub-prolate (1.15–1.33 μm), prolate (1.34–2 μm), and perprolate (>2 μm). The exine ornamentation was perforated-striate, and two different types were identified. The result of quantitative characters has paltry taxonomic importance. The characters studied here delimit at generic level for some genera but not at species level. The obtained result was partially consistent with that of molecular studies published earlier. The pollen size and shape were found to be different between Asian and American species of Photinia. Especially exine sculpture was found to be an important feature to distinguish species of all genera studied. PCA analysis showed that the pollen shape, pollen sculpture, pollen size, and polarity are the key characters to distinguish the species of Photinia and the closely related genera in subfamily Maloideae. Based on pollen exine, two groups (Type I and Type II) were distinguished. The aim of the present study was to find out the taxonomic significance of palynomorphological characteristics in subfamily Maloideae (Rosaceae).

Palyno-morphological investigations of subtropical endangered flora of Capparidaceae through light and scanning electron microscopy.

The research was performed to investigate pollen morphology of endangered species of Capparidaceae in subtropical regions of Pakistan. The distinguishing characters were investigated by using light microscope and scanning electron microscope. Palynological study is comprised of pollen shape, pollen type, exine sculpturing, polar and equatorial diameter, length and width of colpi, mesocolpium, and exine thickness. In polar view, Cleome viscosa exhibited the highest pollen size 26.4 (32.7-24.5 μm) ±0.776 whereas Capparis spinosa appeared to be the lowest 12.6 (14.5-10.7 μm) ±0.400. In equatorial view, Cleome viscosa had the largest pollen size 17.1 (20.0-15.0 μm) ±0.606 and Capparis spinosa had the smallest pollen size 9.7 (12.50-8.00 μm) ±0.394. The maximum fertility percentage has been observed in Capparis spinosa, that is, 98.96% and minimum in Cleome viscosa, that is, 82.93%. Diagnostic key has been constructed to state the essential diagnostic features by means of which the taxa can be identified. Remarkable variations have been observed in pollen size, shape, and exine sculpturing. All the selected species were tricolporate. Prolate to subprolate pollen were observed. There is a great variation existed in exine sculpturing such as in Capparis decidua and C. sp. nova sculpturing is reticulate, in Capparis himalayensis sculpturing is Scabrate granulate, in Capparis spinosa sculpturing is Psilate, in Cleome viscosa sculpturing is regulate-reticulate, in Dipterygium glaucum sculpturing is regulate and in Gynandropsis gynandra sculpturing is striate-regulate. On the basis of overall characteristics of pollen it seems that palynology of this family is helpful at the generic and specific level.

The debate on the publishing of the memoirs of Mikhail Muravyov and its impact on the development of the historiography of the 1863–1864 Uprising

The Uprising of 1863–1864 is one of the most controversial issues in Belarusian history of the period when Belarus was a part of the Russian Empire. This issue started being controversial in the 19th century; one of the important reasons for discussions was the source study factor. One of the most commonly used sources on the events of 1863–1864 was the memoirs of the Vilna Governor-General Mikhail Muravyov, published in the Russian Antiquity (Russkaya Starina) magazine. They sparked heated debate among historians and publicists; the subject of the debate was numerous cases of biased interpretation of historical facts by M. Muravyov; self-glorification and lies. Such figures as Mikhail Semevsky (the publisher of the memoirs); Nikolai Berg; Yevgeniy Karnovich; Pyotr Valuev; Sergei Yuzhakov; Alexandr Pavlov; Ivan Aksakov; Alexandr Mosolov and others were the participants of the discussion. In general; the participants were divided into two groups – critics and supporters of Muravyev. The firsts sought; based on the critic of the Muravyov postulates; to reveal the distortions and to present more objective picture of what had been happening; the seconds supported and justified everything that had been written in every possible way. The discussion confirmed the presence in the Russian historiography of the polar views and assessments of M. Muravyov as a person and as a statesman in the position of the Governor-General of Vilna; as well as attracted additional attention of historians to the issue of the Uprising in general.

Taxonomic importance of spore morphology in Thelypteridaceae from Northern Pakistan

Spore morphology of Thelypteridaceae species growing in Malakand Division, Northern Pakistan, was studied using both light microscopy and scanning electron microscopy. The taxa are Christella dentata and Glaphyropteridopsis erubescens in the subfamily Thelypteridoideae, and Phegopteris connectilis, Pseudophegopteris pyrrhorhachis, and Pseudophegopteris levingei in the subfamily Phegopteridoideae. The studied species exhibit differences in spore size, exospore thickness, color, and ornamentation. Spores of the studied species are monolete and medium-sized, and shape is ellipsoidal in both polar and equatorial views. The average measurement of the polar diameter ranges from 27 μm to 31 μm, whereas in the equatorial direction it varied from 20 μm to 40 μm. The exospore thickness ranges from 1.2 μm to 2.4 μm. Reticulate, laevigate with microgranules, cristate, and coarsely echinate surface ornamentation are observed among the species. Multivariate analysis including unweighted pair group method with arithmetic mean and principal component analysis was used for the grouping and discrimination of species and genera.

Policy over party: comparing the effects of candidate ideology and party on affective polarization

AbstractAt least two theories have been offered that explain the rise of affective polarization. Some scholars, relying on social identity theory, argue that as the relevance of party identification increased, Americans became more likely to see their in-party in positive terms and the out-party in negative terms. Other scholars argue that affective polarization is a reaction to increasingly extreme political actors. This study seeks to arbitrate between these two theories of affective polarization through a survey experiment which asks respondents to rate candidates whose party (or lack thereof) and ideology (or lack thereof) is randomly assigned. In line with the policy-oriented view of affective polarization, respondents reacted far more strongly to ideology than party, especially if it was the ideology of the member of the out-party.

Pollen morphology of Myrtaceae visited by social bees

This study aimed to characterize species of Myrtaceae belonging to genera already identified in the pollen spectrum of beehive products of social bees, describing pollen grains morphology and correlating with taxonomic differences the species reported in the literature. For each plant species, measurements were made with 25 pollen grains in equatorial view and the polar diameter (PD) and equatorial diameter (ED) were measured. The exine thickness was obtained by measuring 10 pollen grains in polar view at the medium height of mesocolpium. The description of pollen morphology showed that pollen grains of the species are triangular amb, 3-colporates, psilate surface, small to medium size and oblate shape with the P/E ratio ranging from 0.52 to 0.72 µm. The morphological description of Myrtaceae species showed similarity between several characteristics common to pollen grains of this species. The description also allowed separation of nine species studied by size and specific morphological characters with the identification key, which can also be used to study the pollen spectrum of hive products.

A palynological survey of the genus Iberis (Brassicaceae), known as candytufts, in Turkey

The present study reports for the first time detailed palynological traits of the Turkish species Iberis. Both light microscope (LM) and scanning electron microscope (SEM) were used for the characterisation of the species. Radially symmetrical, isopolar, and tricolpate pollen grains were observed as common characters in all of the examined taxa. The pollen grains were prolate-spheroidal with polar axes ranging from 21.97 to 29.25 µm and equatorial axes ranging from 20.34 to 26.09 µm. Their polar shapes were subcircular to subtriangular. Two types of exine ornamentation were observed using a SEM. A numerical UPGMA analysis showed that the dimensions of polar axes, equatorial axes and outline in polar view (amb) were the most valuable variables for separating the Iberis species.